The present invention is related to the following pending and commonly assigned U.S. patent applications: INK PRESSURE REGULATOR FOR A THERMAL INK-JET PRINTER, application Ser. No. 08/302,077, filed Sep. 7, 1994, now U.S. Pat. No. 5,541,632, issued Jul. 30, 1996, which in turn is a continuation of application Ser. No. 07/928,811 filed Aug. 12, 1992 now abandoned, by Tofigh Khodapanah et al.; COLLAPSIBLE INK RESERVOIR STRUCTURE AND PRINTER INK CARTRIDGE, application Ser. No. 08/240,297, filed May 9, 1994, which in turn is a continuation of application; application Ser. No. 07/929,615, filed Aug. 12, 1992, now abandoned, by George T. Kaplinsky et al.; COMBINED FILTER/AIR CHECK VALVE FOR THERMAL INK-JET PEN, by George T. Kaplinsky, application Ser. No. 07/995,109, U.S. Pat. No. 5,426,459 filed Dec. 22, 1992 now U.S. Pat. No. 5,426,459, issued Jun. 20, 1995; DOUBLE COMPARTMENT INK-JET CARTRIDGE WITH OPTIMUM SNOUT, by David W. Swanson et al., application Ser. No. 07/995,221, filed Dec. 22, 1992, now abandoned; THERMAL INK-JET PEN WITH A PLASTIC/METAL ATTACHMENT FOR THE COVER, by Dale D. Timm, Jr. et al., application Ser. No. 07/994,810, filed Dec. 22, 1992; THIN PEN STRUCTURE FOR THERMAL INK-JET PRINTER, by David W. Swanson, et al., application Ser. No. 08/266,447, filed Jun. 28, 1994, now U.S. Pat. No. 5,491,502, issued Feb. 13, 1996, which in turn is a continuation of application Ser. No. 07/994,809 filed Dec. 22, 1992, now abandoned; RIGID LOOP CASE STRUCTURE FOR THERMAL INK-JET PEN by David W. Swanson et al., application Ser. No. 07/994,808, U.S. Pat. No. 5,451,995 filed Dec. 22, 1992, now U.S. Pat. No. 5,451,995, issued Sep. 19, 1995; SPRING-BAG PRINTER INK CARTRIDGE WITH VOLUME INDICATOR, by David S. Hunt et al., application Ser. No. 07/717,735, filed Jun. 19, 1991; now U.S. Pat. No. 5,359,353, issued Oct. 25, 1994 and NEGATIVE PRESSURE INK DELIVERY SYSTEM, by George T. Kaplinsky et al., application Ser. No. 07/995,851, filed Dec. 23, 1992; the entire disclosure of which are incorporated herein by this reference.
This invention relates to ink reservoirs for thermal ink-jet ("TIJ") print cartridges, and more specifically to a polymer blend composition useful for ink jet printer applications.
TIJ technology is widely used in computer printers. Very generally, a TIJ includes a print head typically comprising several tiny controllable ink-jets, which are selectively activated to release a jet or spray of ink from an ink reservoir onto the print media (such as paper) in order to create an image or portion of an image. TIJ printers are described, for example, in the Hewlett-Packard Journal, Volume 36, Number 5, May, 1985, and Volume 39, Number 4, August, 1988.
Plastic components used for printers must provide a variety of properties. Specifically, polymer blends used in making the plastic components must be compatible with other polymers used in making the other components that comprise the printer and must be compatible with the inks used in the printer. When the polymer blend is used in printer cartridges, the polymers are exposed to inks which have a variety of materials which may chemically attack the polymers. When the polymers are weakened by the ink, stress cracks may lead to ink leakage and smearing of the printing images.
Another problem for polymer blends used in ink cartridges, is compatibility with the other polymers used in the construction of the ink cartridge itself. Usually, the polymers are formed into films and sealed together to form the ink cartridges. The polymer blend composition has excellent adhesion to the film structures as well as to the other polymeric components of the ink cartridge.
Accordingly, it is desirable to have polymer blend compositions which are resistant to chemical attack and stress cracking. Further, it is desirable to have polymer blend compositions which are compatible with the polymeric components of the ink cartridge.